WASHINGTON--In an age of omnipresent cell phone, Internet and BlackBerry users, why does the government rely primarily on analog television and radio to beam its national emergency alerts?

Politicians asked that question--and urged support for legislation aimed at expanding the Cold War-era system--at a U.S. House of Representatives subcommittee hearing here Thursday.

The hearing focused primarily on the Warning, Alert and Response Network, or WARN, Act, which was formally proposed last week by Illinois Republican John Shimkus and Maryland Democrat Albert Wynn. That bill calls for government and the private sector to devise a "voluntary" national alert system capable of transmitting messages "across the greatest possible variety of communications technologies," including wireless devices and the Internet.

"What we must strive for is an emergency system that leaves no one behind," said Michigan Republican Fred Upton, chairman of the telecommunications and Internet subcommittee.

The existing system, first deployed by President Harry Truman in 1951 with the intention of warning Americans about impending nuclear threats, requires national presidential alerts to be transmitted through analog radio, television and cable systems. Now called the Emergency Alert System, or EAS, it is also available for use by state and local governments on a voluntary basis.

The idea of expanding the warnings to other media appears to have escalated in popularity since Hurricane Katrina and the communications bungles that occurred during the storm. Last November, the FCC issued rules requiring that digital television, cable and audio broadcasters and satellite radio operators also deliver the alerts, beginning Dec. 31, 2006. Satellite television providers must meet that requirement by May 31, 2007.

The FCC itself is still contemplating whether the current structure of the EAS remains the best way to get the word out and is reviewing public comments on whether to deploy a new type of system, such as a satellite or Internet-based mechanism, Julius Knapp, acting chief of the FCC's Office of Engineering and Technology, told the politicians. A recent executive order from President Bush and a report by an independent FCC panel reviewing communications during Katrina have also called for improvements.

The WARN Act, for its part, would not explicitly require the messages to be sent to devices like cell phones and e-mail accounts, because "voluntary, incentive market-based competitive products (do) a better job of encouraging full deployment," Shimkus said.

Instead, details would be worked out by a new government office and a working group composed of federal, state and local government representatives and experts from industries related to the system. That working group would have a year from the law's passage to recommend guidelines, technological standards and other protocols, for any new alert systems.

That idea drew applause from Christopher Guttman-McCabe, a vice president at CTIA-The Wireless Association, who said, "The initial service must be approached with caution, as limits and concerns about capacity and content might arise during an actual emergency."

He endorsed the WARN Act's "sensible" working-group approach, saying he worried that if the industry doesn't play an active role in setting standards for an expanded system, wireless phone users and manufacturers could run the risk of having to swap out billions of dollars worth of handsets that don't work with the EAS.

Others on the panel, including the sheriff of Prince George's County, Md., and representatives from a large pager company, a trade association for public television stations, and a low-power radio project, said they approved of the bill but would prefer that an expanded system be mandatory.

After all, a number of companies already make and sell products that can send out mass warnings, some witnesses told the politicians.

At the hearing, John Lawson, chief executive officer of the Association of Public Television Stations, carried out a live demonstration of how public radio stations can transmit emergency alerts to various media. After Lawson contacted an off-site Federal Emergency Management Agency representative, a red ticker reading "This is a test of the digital emergency alert system," appeared on a computer screen shown on televisions in the hearing room. Committee Chairman Upton reported that the same message had been sent to his BlackBerry, which had apparently been added to the test distribution list.

Some have nonetheless criticized the alert network as yet another expensive government undertaking that doesn't have the same necessity in an era of readily available news. The system was never activated during the Sept. 11, 2001, attacks, even in the New York and Washington metropolitan areas, for instance. And local and state governments failed to activate it for Hurricane Katrina.

Particularly in rural areas, "most (broadcasters) just went on the air full-time, and that in many cases was more productive than a sometimes garbled EAS message traveling in a chain from station to station," Rep. Greg Walden, an Oregon Republican, said at the hearing, though he acknowledged it was important to build "redundancy" into the alert system.